The present invention relates to an optical apparatus which uses a liquid crystal device.
Holography has commonly been used as means for controlling the wave front of coherent light. Various types of information apparatus which use a holographic device have been developed and some of them have been put into practical use as a laser scanner or optical disk head.
Since holographic devices are manufactured using a recording material, such as a silver halide photosensitive emulsion or a photo-resist, such devices must be reconstructed each time the requirements for the holographic device change. The man-hours and equipment investment required for reconstruction are a great burden to the manufacturer.
By providing a programmable function for controlling the light wave front by use of a liquid crystal device exhibiting the desired light wave modulation characteristics, the foregoing problem is solved.